How To Improve HRV: Slow Breathing, The Out-Breath And Yoga
How to improve HRV: the short answer
Did you know your heart speeds up every time you breathe in and slows every time you breathe out? That small rise and fall is heart rate variability (HRV), how flexibly your heart rate changes from beat to beat. If you want to know how to improve HRV, the best-measured way is slow breathing, with a long, soft out-breath. In a 2022 review of 223 studies, slow breathing raised HRV during practice, straight after it, and after weeks of practice. Here is the article in short form.
- HRV is how much the gaps between heartbeats change. A flexible heart is a healthy sign.
- Long stress tends to make the heart rate rigid.
- The heart speeds up on the in-breath and slows on the out-breath.
- Slow breathing raised HRV in a review of 223 studies.
- Try about 5 breaths a minute: 5 seconds in, 5 to 6 seconds out.
- Research on yoga and HRV is promising, and still being studied.
- In Darwin, learn it in class or live online. New students get 12 classes for $59.50.
Last updated: 25 October 2026.
A quick word on Iyengar yoga. Iyengar yoga is the style developed by Mr BKS Iyengar. In the 20th century he did more than anyone to set down traditional Indian yoga, through his books and his teaching, and he pioneered the use of props. It is the style we teach at Flametree, in Darwin and live online.
A healthy heart is not a metronome. Heart rate variability is how much the gaps between beats change.
What is heart rate variability?
Heart rate variability is the small change in the time between one heartbeat and the next. Your heart does not tick like a metronome (a machine that keeps perfect time). At rest, it beats a little faster, then a little slower, then faster again.
A heart that changes flexibly is a sign that its brake is working well. The brake is the vagus nerve (the long nerve that slows the heart and calms the body). Without the brake, the resting heart would beat about 90 to 100 times a minute. With it, the rate is held down to 60 to 75.
When stress goes on and on, the heart rate tends to become rigid, with every gap much the same. That is why people search for ways to improve HRV. They want a heart that can flex again. Our guide to vagus nerve exercises and our page on nervous system regulation explain the brake in more detail.
Why does the heart speed up when you breathe in?
When you breathe in, the brake eases off a little and the heart speeds up. When you breathe out, the brake presses down and the heart slows. This happens in everybody, and it is the single biggest piece of HRV.
Here is the useful part. If you make the out-breath long and slow, you hold the brake down for longer. That is how breathing changes the heart.
Mr Iyengar taught this long before any trial: “The proper rhythmic pattern of slow, deep breathing soothes the nerves, and checks emotional excitement.” His daughter Geeta put it in one line in her classes: slow, soft, quiet exhalation, “so the brain cells quieten.”
Each breath in speeds the heart a little. Each breath out slows it. A longer out-breath gives the brake longer to work.
How to improve HRV with slow breathing
This is the practice with the best measured results. It is simple, and it costs nothing.
- Sit or lie down comfortably. A chair, or a bed with a pillow under the knees, will do.
- Breathe in through your nose for about 5 seconds. Let the belly and lower ribs widen.
- Breathe out gently for 5 to 6 seconds. Make it soft, like fogging a window.
- Keep going for 5 minutes. That is about 5 to 6 breaths a minute.
- Keep it soft. If you strain, make the count shorter. Never force it.
Most adults breathe 12 to 20 times a minute, so this is a big slowing. Go there slowly. Count 4 in and 4 out for a week, then 5 in and 5 out.
Try slow breathing in five steps. About 5 to 6 breaths a minute is the aim.
What is coherent breathing?
Coherent breathing is the name given to this slow rhythm by two American psychiatrists, Dr Richard Brown and Dr Patricia Gerbarg. They have taught breath practice to patients, disaster survivors and soldiers for many years. In their book The Healing Power of the Breath (2012), they call it their favourite practice.
The aim is about five breaths a minute, which is six seconds in and six seconds out, gently, through the nose. They write that each of us has a “resonant” rate (the speed at which HRV is highest), somewhere between about three and a half and six breaths a minute. You can find yours by trying 4, 5 and 6 breaths a minute and noticing which one feels most settled.
That is known from practice, and early studies are encouraging. Their research had no control groups in most cases, so larger trials are still needed.
A tall, easy seat on a blanket is a good place for slow breathing. Let the shoulders drop and the breath go quiet.
What does the research say about HRV breathing?
Practice, research and ongoing study each have something to say.
Supported by research. A 2022 review of 223 studies found that slow breathing raised HRV while people were doing it, straight after one session, and after weeks of practice (Laborde and colleagues, Neuroscience and Biobehavioral Reviews). A 2018 review of 15 studies of breathing under 10 breaths a minute found more comfort, relaxation and alertness, and less anxiety, anger and confusion (Zaccaro and colleagues, Frontiers in Human Neuroscience).
Promising, and still being studied. For yoga as a whole, the picture has been mixed. A 2015 review of 14 trials found only two of good quality, and no convincing evidence on HRV (Posadzki and colleagues). Newer reviews are more encouraging. A 2018 meta-analysis of 17 trials of Tai Chi and yoga found better HRV and lower stress (Zou and colleagues, Journal of Clinical Medicine). A 2025 review of four trials in students found yoga improved HRV and anxiety, and its authors said more rigorous studies are needed (Sharma and colleagues, Annals of Neurosciences).
Known from practice. Iyengar teachers have taught slow, smooth breathing for generations, and students commonly find it calms them within a few minutes.
One trial is worth knowing. A 2023 Stanford trial found five minutes a day of slow breathing for a month lifted mood and slowed the resting breath. Longer practice, and a good teacher, may matter. Balasubramanian puts it well: you cannot directly control your heart rate, but you can change your breath.
A 2022 review of 223 studies found that slow breathing raises HRV: during practice, straight after it, and after weeks of practice.
How does yoga help your HRV?
A class helps in three ways. First, the slow breath. Second, rest poses that let the body switch off. Third, the steady rhythm of a weekly class, because HRV rose after weeks of practice, not after one session.
Two poses are favourites for calming the heart. Legs Up The Wall, below, is a restful pose where you lie back with the legs resting on a wall and a bolster under the hips. Supported lying pranayama (breathing practice), shown after it, lets you lie over bolsters and breathe slowly with an eye cover on.
Legs up the wall, with a bolster under the hips. Five calm minutes of long out-breaths.
Supported lying pranayama with bolsters and an eye cover. The props hold you, so the breath can slow down on its own.
For more on the whole-body picture, see our guides to how to calm your nervous system and yoga for stress management.
Get the free ebook Cutting Stress With Yoga. New to Flametree, or away for 3 months or more? You get 2 free classes + 2 ebooks, only available via this offer. Already coming to class? You can still get the book.
Where can I learn HRV breathing in Darwin?
For HRV breathing in Darwin, come to a beginner class at Flametree’s Woolner or Coolalinga studio, or join live online. We run 17 beginner classes a week in Darwin, and seven are also live online. Studio classes are for permanent NT residents, and online classes are open from anywhere.
You will learn the breath on a bolster or a chair, with a teacher who watches how you are doing. Times are on the beginner timetable, and the picture there is the master copy.
The easiest way to start is our beginner deal: 12 classes for $59.50 (10 at half price plus 2 free), for new students or those away three months or more, with a 14-day money-back guarantee.
Frequently asked questions
What is heart rate variability?
Heart rate variability (HRV) is how flexibly your heart rate changes from beat to beat. The gaps between beats change a little with each breath. Long stress tends to make them rigid.
How to improve HRV fast?
Slow breathing is the best-measured way. Breathe in through the nose for about 5 seconds and out gently for 5 to 6 seconds, for five minutes. HRV rose during and straight after slow breathing in a review of 223 studies.
Why does my heart speed up when I breathe in?
On the in-breath the vagus nerve brake eases off and the heart speeds up. On the out-breath the brake presses down and the heart slows. A long out-breath holds the brake down for longer.
What is HRV breathing?
HRV breathing is slow, even breathing at about 5 to 6 breaths a minute, with a smooth, soft out-breath. It is also called coherent breathing.
How many breaths a minute is best for HRV?
About five, which is six seconds in and six seconds out. Brown and Gerbarg say each person has a resonant rate between about 3.5 and 6 breaths a minute where HRV is highest.
Does yoga improve HRV?
Newer reviews are encouraging. A 2018 review of 17 trials of Tai Chi and yoga found better HRV and lower stress. Earlier reviews were mixed, and studies are still being done.
How long until HRV improves?
Slow breathing raised HRV during practice and straight after it. Higher HRV after weeks of practice was also found, so a steady routine matters.
Where can I learn HRV breathing in Darwin?
Flametree Yoga Studio teaches slow breathing in beginner Iyengar yoga classes at Woolner and Coolalinga, and live online. New students get 12 classes for $59.50.
Where to next
- New to yoga, or coming back? Start with our half price 10 class pass with 2 classes free, in Darwin or live online.
- Want help with stress? Try the Yoga For Stress pass, in Darwin or live online.
- For a workplace, team or group: book private yoga classes for groups, online, at a Flametree studio or at your venue.
- Want to see class times first? Look at the beginner timetable.
Flametree Yoga Studio, Darwin and live online. This article is general information, not medical advice.
Sources: Laborde S and colleagues, Effects of voluntary slow breathing on heart rate and heart rate variability, Neuroscience and Biobehavioral Reviews, 2022; Zaccaro A and colleagues, How breath-control can change your life, Frontiers in Human Neuroscience, 2018; Posadzki P and colleagues, Yoga for heart rate variability: a systematic review and meta-analysis of randomized clinical trials, Applied Psychophysiology and Biofeedback, 2015; Zou L and colleagues, Effects of mind-body exercises (Tai Chi/Yoga) on heart rate variability parameters and perceived stress, Journal of Clinical Medicine, 2018; Sharma S and colleagues, Effect of yoga-based interventions on heart rate variability and anxiety among students, Annals of Neurosciences, 2025; Brown RP and Gerbarg PL, The Healing Power of the Breath, 2012.
